基于51的超声波测距代码+原理图（含温度补偿）

//增加了按键和LED指示灯，注意按键要一直按下自锁，按键右边有个红色的东西，鼠标点一下可以自锁 //温度补偿可以正常使用了，按按键可以切换加温度补偿还是不加温度补偿 //仿真还有一些不稳定，但算是正常了 //注意两个按键不要同时按下 //没按按键时显示9999 //距离超出3000mm或小于2mm，蜂鸣器会响，但是仿真达不到2mm，最小只能达到30mm #include <reg52.h> #include <intrins.h> #define uchar unsigned char #define uint unsigned int sbit Trig = P1^7; //超声波发送信号 sbit Echo = P3^2; //超声波接收信号 bit timeout_flag = 0; //接收超时标志，距离过长或超声波未响应 sbit DQ = P3^0; //温度传感器 sbit BUZZER = P3^7; //蜂鸣器 sbit Key0 = P3^3; //不加温度补偿自锁开关 sbit Key1 = P3^4; //加温度补偿自锁开关 sbit LED0 = P3^5; sbit LED1 = P3^6; void bcd(uint setdata); void display(uint setdata); //显示距离d(distance) void delayms(uint t); void delayus(uint us); void Get_distance_Data(); uint diatance_Conut(); uint DS18B20_init(); void write_byte(uchar dat); uchar read_byte(); uint read_temper(); uint temper_change(); float time; //超声波传播时间 float distance = 9999;//显示9999或0（其实达不到2mm，软件仿真最小只有30mm）即为超出范围 float Temperature = 25; uchar num1[4]; //储存四位数字 uchar code ledval[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e}; uchar code ledpoint[]={0xf1,0xf2,0xf4,0xf8}; void main() { LED0 = 1; LED1 = 1; BUZZER = 0; TMOD = 0X11; TH0 = 0; TL0 = 0; ET0 = 1; //允许T0中断 // TH1 = (65535 - 20000)/256; // TL1 = (65535 - 20000)%256; // TR1 = 1; // ET1 = 1; //允许T1中断 EA = 1; DS18B20_init(); while(1) { Get_distance_Data(); distance = diatance_Conut(); display((int)distance); // display((int)temper_change()); } } void Get_distance_Data() { Trig = 1; delayus(22); Trig = 0; Trig = 1; delayus(22); Trig = 0; while(!Echo); TR0 = 1; while(Echo); TR0 = 0; } uint diatance_Conut() { uint S; time = TH0*256+TL0; TH0 = 0; TL0 = 0; if(Key1 == 1 && Key1 == 1) { S = 9999; LED0 = 1; LED1 = 1; BUZZER = 0; } if(Key0 == 0 && Key1 == 1) { S = (time*0.34)/2.0; //温度补偿前，显示为mm LED0 = 0; LED1 = 1; } if(Key1 == 0 && Key0 == 1) { Temperature = temper_change(); S = (331.45+0.61*Temperature)*time/2000; //温度补偿后，显示为mm LED0 = 1; LED1 = 0; } if(Key1 == 0 || Key0 == 0) { BUZZER = 0; if(S>=3000) { S = 9999; BUZZER = 1; } if(S<=2) { S = 0; BUZZER = 1; } if(timeout_flag == 1) { S = 9999; BUZZER = 1; timeout_flag = 0; TH0 = 0; TL0 = 0; } } return S; } void timer0mode1() interrupt 1 { timeout_flag = 1; } //void timer1mode1() interrupt 3 //{ // TH1 = (65535 - 20000)/256; // TL1 = (65535 - 20000)%256; // TR1 = 0; // Temperature = temper_change(); // TR1 = 1; //} void display(uint setdata) { uchar i; bcd(setdata); for(i=0;i<4;i++) { P2=ledpoint[i]; //数码管位选 P0=ledval[num1[i]]; //数码管段选 delayms(2); } } void bcd(uint setdata) { num1[0]=setdata/1000; num1[1]=(setdata%1000)/100; num1[2]=((setdata%1000)%100)/10; num1[3]=((setdata%1000)%100)%10; } //ms级延时 void delayms(uint t) { uchar i; while(t--) { for(i=0;i<120;i++) {;} } } //us级延时 void delayus(uint us) { while(us--); } uint DS18B20_init() { uchar i; DQ=1; delayus(1); //稍作延时 DQ=0; delayus(80); //延时480到960us DQ=1; i = 0; while(DQ) //等待DS18B20拉低总线 { delayms(1); i++; if(i>5)//约等待>5MS { return 0;//初始化失败 } } return 1; } void write_byte(uchar dat) //写一个字节 { uchar i; for(i=0;i<8;i++) { DQ=0; //每写入一位数据之前先把总线拉低1us _nop_(); DQ=dat&0x01; //取最低位写入 delayus(10); //延时68us，持续时间最少60us DQ=1; //然后释放总线 dat=dat>>1; //从低位开始写 } delayus(10); } uchar read_byte() //读一个字节 { uchar i,dat=0, bi; for(i=0;i<8;i++) { DQ=0; //先将总线拉低1us _nop_(); DQ=1; //然后释放总线 _nop_(); _nop_(); _nop_(); _nop_(); // if(DQ) dat=dat|0x80; //每次读一位 // dat=dat>>1; //从最低位开始读 bi = DQ; dat = (dat >> 1)|(bi << 7); delayus(10); //读取完之后等待48us再接着读取下一个数 } return dat; } uint read_temper() { uchar a,b; uint t=0; DS18B20_init(); delayms(1); write_byte(0xcc); //跳过ROM操作命令 write_byte(0x44); //发送启动温度转换命令 DS18B20_init(); delayms(1); write_byte(0xcc); //跳过ROM操作命令 write_byte(0xbe); //发送读温度寄存器命令 a=read_byte(); //先读低八位 b=read_byte(); //再读高八位 t=b; t<<=8; //左移八位 t=t|a; //t为16位的数，使高八位为b的值，低八位为a的值 return t; //返回温度值 } uint temper_change() { int temper; float tp; temper=read_temper(); if(temper<0) //考虑负温度的情况 { temper=temper-1; temper=~temper; tp=temper*0.0625; //16位温度转换成10进制的温度 temper=tp+0.5; //四舍五入 } else { tp=temper*0.0625; //16位温度转换成10进制的温度 temper=tp+0.5; //四舍五入 } return temper; }